Jim Donohue wrote:
As I have pointed out before Jeff you simply read the conclusion you have
already reached into the data. But I will try once more though it will
likely do little good.
You've created quite a "straw man" argument here. You keep assuming
that my position is that GPS is "flawed" as so you keep pointing out
reasons why problems associated with are really the fault of something
else, not the GPS. I've never denied that GPS is the most accurate,
and the most reliable (by some measures). My issue has been the
over-reliance on one mode of navigation, and the best sequence of
education to avoid problems.
Perhaps we should go back to the beginning of this particular issue. I
said, "The NTSB study blamed several "probable causes:" over reliance on
GPS, and lack of training of the officers, and the failure to recognize
the problem from other cues."
You responded with "Find for me any mention of over reliance on GPS."
In fact, I believe I found a number of places where they say just that.
"Jeff Morris" wrote in message
...
Jim Donohue wrote:
....
You've made this claim several times and its total Bull****! You're
claiming, in essence, that because the satellites broadcast a good signal,
there is no problem with over-reliance on GPS. This is a textbook case in
what can go wrong with such over-reliance.
The bizarre thing here is that on one hand you've been arguing that GPS
should be learned first because it is nearly perfect, but then here you're
claiming that the problem was the "incompetent seaman" who relied too much
on GPS.
To the contrary...two GPSs integrated into the system would have fully
solved the problem. Or integrating the LORAN would have worked as well.
You're right. There are any number of possible changes that would have
prevented this particular grounding. What will prevent the next? How
about looking at the depth sounder as you approach shore? How about
noticing that the island that was sighted should have been 30 miles away?
There are places where the LORAN would not work so for a broad solution it
is not as useful as the second GPS. But two GPS or three GPS and the LORAN
would have been fine.
Unless someone spilled a Pepsi on the control panel and popped a fuse.
You don't understand failure analysis, do you?
We agree they were over-reliant on the automatic bridge system. We agree
that they should not have been dependent on a single navigational device.
But this single device reliance is a fault of the bridge system design not
the GPS.
Again with the "straw man" argument!
If either the LORAN or, better, a second GPS the failure would not
have occurred. We would also suggest an automatic cross check or at least a
manual one was a minimum requirement for the operation of the bridge. The
automatic bridge system was defective and the staff incompetent...what more
needs to be said?
What a tangled web you're weaving here! When I first heard of the
accident (lots of coverage here in Boston, of course) I was appalled
that they would have made the approach without once looking at the depth
sounder to verify they were in the channel. One minute of human
intervention, using a technique that should have been second nature to
any experienced boater.
And you're claiming that that should not have been necessary - what was
needed was two GPS's and a LORAN, all powered presumably by separate
power sources, feed a computer that will compare and sound the alarm if
there;s a discrepancy. And if the computer fails? NASA's approach for
Apollo was to use 5 360's for double redundancy plus cross checking.
(Not to mention links to other locations in the country that could take
over.) Fortunately, they remembered to include some eyeball navigation
tools or Apollo 13 would not have returned.
And, while you might be able to make a case that such equipment is
appropriate for a cruise ship, we're still a few years away from having
this for the average boater.
In the "Conclusions" section of the report the NTSB describes what
happened and what went wrong. The majority of the 22 conclusions talk
about the failure of the GPS (mentioning it specifically) system or the
failure to double check by other means, i.e. the over-reliance on one
system.
Here's some examples:
5. Had the fathometer alarm been set to 3 meters,
as was the stated practice, or had the
second officer chosen to display the
fathometer data on the control console, he
would have been alerted that the Royal Majesty
was in far shallower water than expected
and, thus, was off course. He would
have been alerted perhaps as long as 40
minutes before the grounding, and the
situation could have been corrected.
Nothing GPS...simply incompetent bridge operation.
Failure to use traditional piloting techniques. One for me!
6. The watch officers’ monitoring of the status
of the vessel’s global positioning system
was deficient throughout the voyage from
St. George’s.
Does mention GPS but is actually directed at the monitoring of the system.
Suggests the monitoring was deficient not the GPS.
Assuming the GPS was perfect. Another for me!
7. Deliberate cross checking between the
global positioning system and the Loran-C
to verify the Royal Majesty’s position was
not being performed and should have been
on the voyage from St. George’s.
Such a procedure supposedly existed according to the Navigator and Chief
Officier. So failure to follow established procedures indicts the GPS?
Nahh
Yup! Overreliance on one technique - this is a perfect example.
Another for me!
8. Even though it is likely that the watch officers
were not aware of the limitation inherent
in using the position-fix alarm to monitor
the accuracy of GPS position data, it was
inappropriate for them to rely solely on the
alarm to warn them of any problems with
the GPS data.
Are boys did not know how the system worked. Clearly not a GPS problem.
The appropriate handling of alarms and errors is a bridge sytem problem.
What? You're admitting that its possible to make a mistake using GPS?
but, you said it was perfect! Maybe, if the had used more than one
technique ... Score one more for me!
9. The sighting of lights not normally observed
in the traffic lanes, the second officer’s inability
to confirm the presence of the BB
buoy, and the sighting of blue and white
water should have taken precedence over
the automation display on the central console
and compelled the second officer to
promptly use all available means to verify
his position.
The incompetence included denying the obvious. That is not a GPS problem.
So your point is that GPS is perfect, its the humans that caused all of
the problems. But it was the GPS system that "mislabeled" the buoys on
the chart. How was this not a GPS problem? Score one more for me!
10. The chief officer and the second officer did
not observe good watchkeeping practices or
act with heightened awareness of the precautions
that are needed when a vessel approaches
the Boston traffic lanes and landfall.
Not a GPS problem.
You're correct. This is a problem with overreliance on GPS, just like
I've been saying. Score another for me.
11. The master’s methods for monitoring the
progress of the voyage did not account for
the technical capabilities and limitations of
the automated equipment.
That was really dumb...using a system as the input to a check on its own
accuracy. Dumb.
Yes, it was dumb to rely on the GPS. Just as I've been saying.
12. The watch officers on the Royal Majesty
may have believed that because the global
positioning system had demonstrated sufficient
reliability over 3 1/2 years, the traditional
practice of using at least two independent
sources of position information was
not necessary.
That is a breakdown in the capabilities of the officiers not the GPS.
13. All the watchstanding officers were overly
reliant on the automated position display of
the navigation and command system 25 and
were, for all intents and purposes, sailing
the map display instead of using navigation
aids or lookout information.
Yes they were not competent sailors.
Agreeing, they relied on the GPS and ignored basic piloting techniques.
Just as I've been saying.
The report continues with other items in the same vein, though focused
more on the problems with the integrated system and the training, such as:
16. Had the navigation and command system 25
autopilot been configured to compare position
data from multiple independent position
receivers and had a corresponding alarm
been installed that activated when discrepancies
were detected, the grounding of the
Royal Majesty may have been avoided.
These independent position receivers would likely be multiple GPS with
(perhaps) a LORAN. Remember LORAN is not an all areas system. They would
have almost certainly prevented this problem whether or not a LORAN was
included.
Actually this was an "operator setting" that was at the ship's officers
discretion. They decided that the GPS alone was sufficient.
Nothing wrong with multiple GPS's until the GPS system hiccups. Even if
it stays up 99.99% of the time, there could be hundreds of boats
negotiating a channel at the time. And the display computer provides a
"single failure point," and the antenna feed are probably bundled
together, etc., etc.
Although the "Probable Cause" section which follows does not mention GPS
specifically, it is quite short (two small paragraphs) and mentions simply
"overreliance on the automated features of the integrated bridge system,"
the lack of training, and the failure to take "corrective action after
several cues indicated the vessel was off course." In other words, they
relied too much on one source of position (the gps) and ignored others.
While the "Recommendations" section does not mention GPS specifically, it
clearly recommends against over reliance on one system. We've never
claimed there was anything "wrong" with GPS, only that other forms of
navigation are just as important. The report includes comments like:
Actually I think it says one should not rely on a single input device.
Multiple GPS are much more likely the solution then GPS and something else.
Hopefully not. However, GPS's are so cheap there's nothing wrong with
having two. But where LORAN is available, or Glosnoss, or Galileo (if
it happens), they should be used.
But regardless, there is no excuse for not thinking it odd that a big
island is misplaced by 15 miles.
Review the bridge watchstanding practices
on all its vessels, and revise, as
necessary, to ensure that all watch officers
adhere to sound watchstanding
practices and procedures, including using
landmarks, soundings, and navigational
aids to verify a vessel’s position,
relying on more than one source for position
information, and reporting to the
master any failure to detect important
navigational aids.
...
As I have said before failure to look out the window and at the RADAR and
using what you see to verify that all is working correctly is incompetence
upon the part of a bridge officier.
We we agree on that. Overreliance on GPS is bad.
As part of the foreign flag passenger
ship control verification examination
program, verify that the watchstanding
procedures of ships’ officers include the
use of multiple independent means of
position verification.
It is true that the bulk of the recommendations have to do with better
standards for automated systems, but even then it deals largely with the
need to use more than one form of input.
comparing position-receiver data for
significant discrepancies between
position receivers, and subsequent
positive annunciation to the crew;
It says nothing as far as I can determine about different "forms" of input.
It suggests multiple receivers. I would think the mostly likely of this
would be multiple GPS.
This depends on how you interpret "multiple independent sources." Two
GPS's aren't exactly "independent." And they are quite explicit that
the traditional piloting techniques should be used to validate the
position reported by the automated system. What part of "landmarks,
soundings, and navigational aid to verify a vessel's position" do you
interpret as meaning two GPS's are sufficient???
Sorry Jim, its clear that you've been disingenuous with us. The NTSB
study is quite specific in finding fault with relying completely on GPS.
Though they don't fault the GPS system itself (i.e. the signal leaving the
satellite) they make it quite clear the overreliance on one electronic
navigation system was the cause of the grounding.
And again you read what you believe not what is there. The NTSB believes
the input should have been redundant both in the automatic system and on the
bridge. So do I. You believe some other "form" should have been
integrated. I believe it was integrated in bridge procedures but was not
performed. Another "form" was not needed though it was there. What was
needed was a level of redundancy either through the system or bridge
operation or, even better, through both. Again the system was deficient as
was crew performance.
And how is this not "over reliance on GPS" as I first claimed? You've
completely agreed with me on every point, yet you fight on against some
"straw man" of your creation. You're a real piece of work, Jim!
Jim
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